Francis a



INVENTOR KLM d. BY

m QzJM/IM/ ATTORNEYS.

Aug. 10, 1926.

I F. A. GUDGER METHOD oF TREATING MICA Filed Feb. l9, l1924 PatentedAug. 1o,- 192s.

UNITED STATESV '1,595,088 PATENT OFFICE.

manon or 'HEATING mea.

application' mea February 1a, 1924. serial 1m ceases.

My invention relates to an improved method for treating mica, beingpartlculary1y directed to the drying and cleaning of the same. f

One of the objects of my invention is the provision of a method andapparatus whereby the mica in its travel through the. apparatus isthoroughly dried and cooled and is finally delivered in such conditionto sacks or other containers in which it is packed for shipment.

Another object of my invention is the provision of a method andapparatus for treating the mica whereby during the drying process thegravel, always' found in scrap or waste mica, is separated from themica. v

The mica which I have in mind as particularly adaptable for treatment bymy improved method comes from the mill in small pieces saturated withwater, the water` being used for the washing process which is performedprior to treatment by my method. l

The diiiicultyv previously encountered in handling this material hasbeen the thorough and eiiicient drying of the material so that the samecould be packed for shipment, and prior to my invention this has beendone by scattering the material over the floor and allowing the same tobe dried by the sun and air. This method, however, is very slow,requires a large floor space for operation, and is generallyunsatisfactory in a commercial sense'.

By my improved method, however, the mica is not only dried but cooled inthe minimum of time, while the space required for the drying apparatusis also materially reduced-in fact, need not be taken into considerationat-all. A further advantage of my improved method is the handling ofthemica by machine throughout so that the labor costs are cut down'as well.

In the practice of my improvedmethod,

the mica as it comes from the millin its saturated or damp condition 'isdumped into a hopper from which it is carried upwardly through a troughby a belt which is suiciently agitated to cause the sand and gravelwhich is mixed with the mica when scrap mica is being treated to, beshaken or jarred out of the mica so that the material whichbut clean-wet mica were being treated, the

first step of my method, as just described, could be eliminated as therewould be no foreign matter mixed with the mica requiring lremoval. Themica after it reaches the end of the first conveyer falls into a secondhopper which is located at the top of a baty tery of drying tubularchambers or cylinders. Each of these chambers vis provided with ahelical conveyer and each chamber is in communication with its neighbor,while lthe conveyers are alternately right and lefthand'so that afterthe material has passed through one chamber it falls u on the nextlowest conveyers to be carried y it in the opposite' direction to itsdirection of travel through the preceding chamber. `In otherV words, thematerial passesfrom left to righ't `and then. fromright torleftalternately un-'r til it finally reaches the bottom chamber of thebattery from which it discharges into a third hopper.` The dryingchambers may be heated in any suitable way, as by steamjacketing, forexample, or in any-other suitable way which lmay appeal to one skilleding operation a blast of heated air may be in this art, and to furtherfacilitate the dgydrawn through the heating chambers during l thepassage ofthe material therethrough, this hot air blast traveling in theopposite direction to that of the travel of the material.

above outlined, While discharging lfrom the heating battery in a heatedand dry condition, is still `not ready for packing, moisture forming oneach particle `of the mica as the same cools. Consequently I \trans ferthe I ind that mica treated in the manner mica from the third hopper toa fourth hopper by means of a conveyer belt running at fairly highspeed, this belt or conveyer transporting the material upwardly throughan enclosed trough from which it is dumped or discharged into aninclined revolving screen of ine mesh, the' material traveling down thisscreen by gravity to thedischarge end thereof. During the passage of the.I

mica from 4the third hopper to the discharge end of the revolvingscreen-the materialis thorou hly cooled so that it may be dischargeAfrom the screen directly into sacks or other containers shipment.

. It will be seen, therefore, that I have provided a method whereby themica to be and packed ready forl treated may'be thoroughly dried in anexpeditious and practicable manner with the minimum of handling and withthe minivany foreign substances, such as sand and gravel, as well. -Y

It is to be understood, and I have attempted to make this point clear 1nthe discussion of my invention, that while I have made particularreferencetoyscrap mica as lending itself to treatment by my method, Iamnot to be limited to the ldryin of scrap mica as'it must be obviousthat can treat y.any kind of fairly finely-divided mica,

whether the same be what is technically known as scrap mica or not.

The type of apparatus which may be employed in the working of mylmproved method may be varied to suit cond1t1ons, but in theaccompanying drawings I have illustrated one form ofxapparatus which Ihave put into commercial operation and found particularly well adaptedfor the practice of my method.

In the accompanying draw1ngs- Figure lis a sectionalelevationall view,more or less diagrammatic, of the apparatus above mentioned which I haveemployed in the actual drying of scrap mica and Fig. 2 is a section ofva part of this apparatus taken on the line 2 2 of Fig. 1.'

Referring to the drawings in detail, 1 designates an intake hopper intovwhich is fedthe wet mica to be treated.' 'In the botl, tom of thishopper I mount a pulley 2,

`carrying a. belt conveyer 3, the other end of tis conveyer beingcarried by a similar pulley 4, at the upper end of an inclined trough 5which is connected to one side of the hopper. The conveyer 3 is providedon its active face at regular intervals with transverse strips or cleats6 and these cleats carry the material from the hopper to the top of thetrough 5 and from thence it falls into a hopper 7. I find in actualpractice that the conveyer belt 3 in passing over the pulleys 2 and 4 isagitated sufficiently to cause the sand and gravel which is mixed withthe scrap mica to be shaken to the ends of the cleats 6 from which itfalls over the sides of the conveyer into ,catchalle or sumps 6 whichmaybe arranged at intervals along the conveyer, these sumps or catc -allspassing the sand and gravel out of te trough entirely.

The mica has now been freed from sand and gravel and after being dumpedinto chamber contains a helical conveyer 10, and i after the ,materialhas traversed the first chamber, from left to right as shown in, thedrawings, it drops into the next chamber immediately below and traversesthat chamber in the opposite direction to the direction of travel of thematerial in the first I chamber. The material traverses eachindividualchamber until it finally reaches the lowest chamber of the battery fromwhich it is discharged through spout 14 into a third hopper 15. Aspreviously'indicated,

The mica, as it is discharged from thel drying battery, is fairly hotand dry, but i I ind in actual practice that in cooling oif moisturewill collect on the small particles of the mica. To eliminate thismoisture and prepare the mica ready for shipment, I provide a secondconveyer 18, one end of which passes into the bottom of the hopper 15, i

while the other end is passed about a pulley y19 at the upper end of anenclosed trough 20. The lower end of the conveyer 18 .passes about apulley 19 in the bottom of the hopper-15. This conveyer, Which issimilar in construction to the conveyer 3, is provided with transversecleats or strips 21, and is driven at fairly high speed and in adirection reverse to that of the conveyer 3, the material being pushedup along the bottom of the trough 20 by the cleats 21, from which itdrops into a ho per 22 at the upper end of an inclined, fair y finemesh, rotary screenl 23. The material passes down the screen 23 bygravity and in its travel down the length.

of this screen, the material is thoroughly dried and cooled so that itmay be discharged from the discharge spout 24 of the screen into sacksor other containers in which it is to be packed for shipment.

.Having particularly described my inventlon, what I claimand desire tosecure by Letters Patent is :--A i 1. The method of drying mica, whichmethod consists -in heating the mica and thereafter cooling bysubjecting the mica to agitation. f

2. The method of drying mica, which method consists iny elevating themica and then effecting a descent of the same through a battery or bankof heated chambers, eleopposite direction,

vating the mica after so heating and finally cooling by effecting asecond descent of the mica while subjeetin to agitation.

3.A The method o drying mica, which method consists in heating the micaby passing the same through a drying chamber hot air traveling in theand finally cooling the heated mica by subjecting the same toagitaagainst a current of 10 tion. y

i f4. The method which consists in agitatmaterial such as sand andgravel, to recover the mica, thereafter heating the re covered mica, andnally assing the heated mica over an incline retlculated, agitated,surface to effect thorough cooling of the mica.

This specification signed this 14th day of February," 1924i.

FRANCIS A. GUDGER.

